Nasopharyngeal Cancers

Diagnosing Nasopharyngeal Cancer

Getting to a diagnosis begins with a history and physical examination. If the symptoms haven’t been present for very long, or if the history and physical examination make the doctor less suspicious that your lesion is cancer, your doctor might try some medications and rehabilitation before reaching a diagnosis of cancer.

At some point, if your doctor is not certain of a diagnosis, and if symptoms aren’t getting better (and definitely if symptoms are getting worse), your doctor should raise the possibility of starting a cancer work-up. Like with most cancers in the head and neck, this will include some combination of biopsy and imaging tests.

Be sure to bring all reports and images from any prior treatment with you to your appointment with your head and neck cancer specialist.

Imaging

Imaging refers to radiologic studies, or scans, that create pictures of the structures inside your head and neck. In general, for small tumors that are easily evaluated on physical examination, imaging might not be necessary. For larger tumors, or tumors in locations that are difficult to examine (including most tumors of the nasopharynx), your doctor will probably order some sort of imaging to get more information about the tumor location and possible spread to regional lymph nodes.

The two main imaging techniques used in the U.S. are computed tomography (CT) scans and magnetic resonance imaging (MRI) scans. Ultrasound is a quick and inexpensive way to get information about disease that is in lymph nodes in the neck. PET scans are studies that look at the function of cells in the body, and they are being used more and more in oncology. PET scans can be combined with other imaging methods such as CT scans to get more detailed information.

CT scan: This is a quick series of X-rays that can show very good detail of the anatomy. It is helpful in seeing the extent of the main tumor mass and what structures it has invaded. It can also help detect spread into the neck.

Advantages: A CT scan is a quick test that is readily available and gives a great deal of useful information.

Disadvantages: A CT scan involves radiation, and the images can be degraded by movement and dental work. It only shows late changes associated with invasion into nerves (such as destruction of the bone where the nerve enters the skull).

Important points: A CT scan looking for throat tumors should be done with a contrast dye that is injected into your veins, unless there is some reason that you cannot receive contrast. Allergies to iodine and shellfish are common indications that a patient may be allergic to contrast dye.

What to expect: First, a nurse will insert an intravenous line into a vein to allow for contrast injection. Then you will have to lie flat on a table with your head in a little holster to help keep it totally still. CT scans are typically open, so you shouldn’t feel enclosed. You will then get an injection of contrast, and soon after, the scanner will start moving and taking pictures; this part should only take one or two minutes. Try not to swallow, speak or move during this quick test.

MRI: This test uses magnets to create a picture of the inside of the neck. It is good for showing more subtle details of how extensive the main tumor mass is. It can also help pick up spread of cancer to lymph nodes in the neck.

Advantages: There is no radiation involved, and the details of the soft tissues are better than that of a CT scan.

Disadvantages: An MRI takes much longer than a CT scan and is more expensive. Some people feel enclosed inside the MRI machine and may require sedation to get through the study.

Important points: This test should be done with and without contrast injected into your veins, unless there is some reason you can’t have contrast. Closed MRI machines usually give better pictures than open MRI machines.

What to expect: First, a nurse will insert an intravenous line into a vein to allow for contrast injection. Then you will have to lie flat on a table with your head in a little holster to help keep it totally still. Due to the strength of the magnets, you will be instructed to remove any metallic objects and to change into a hospital gown before entering the room where the scanner is located. You will then enter the scanner, and the MRI machine will start moving and taking pictures. This can take 30 to 60 minutes, depending on how the scan is done. Try to stay as still as possible throughout the test.

Positron Emission Tomography (PET): Doctors are still studying the most appropriate uses of PET scans for head and neck cancer. The main uses of PET scans at this point are to see if there is spread to sites in the neck or other parts of the body or to help find a primary tumor when the only evidence of cancer is a lymph node that has cancer in it. It is often combined with a CT scan (or in some cases an MRI) to help pinpoint the location of active cells.

Neck ultrasound: An ultrasound is a way to look at vessels, structures and lymph nodes all over the body, particularly in the neck and thyroid gland. You are not exposed to any radiation, and it doesn’t hurt. Basically, a technician or a radiologist will place some cold jelly over the area that is being examined and rub a plastic probe over the area to take pictures. The technician can see enlarged lymph nodes and nodules deep in the neck and describe details about them such as whether they have fluid inside, have a lot of blood vessels around and so on. At the same time that the ultrasound is being performed, a doctor can place a needle into a lymph node or nodule and draw off cells (this is an ultrasound-guided biopsy).

Chest X-ray: This is a quick, inexpensive and easy way to look for signs of spread of cancer into the lungs or the possibility of a different cancer in the lungs. Some doctors will recommend a chest X-ray every year as follow-up if you have had a head and neck cancer. This is because patients who have had head and neck cancer are at a higher risk of getting lung cancer as well.

Biopsy

A biopsy is the removal of a small piece of tissue to examine under a microscope to see if it is cancerous. At some point, you will need a biopsy of the suspicious lesion in your throat. The biopsy report is extremely important for determining your diagnosis and treatment plan.

When performing a biopsy on a neck mass, your doctors should test for certain viruses such as human papillomavirus (HPV) and Epstein-Barr Virus (EBV). They can also test for proteins related to these viruses (e.g. P16 as it relates to HPV infection). Cancerous lymph nodes that have the HPV virus (or P16 protein) are very likely to be related to a primary cancer in the oropharynx. A positive HPV or P16 test should make your doctor spend extra time and effort looking for a small or hidden tumor somewhere in the oropharynx.

Biopsy of nasopharynx lesions

There are a few different techniques that can be used to biopsy a lesion in the nasopharynx.

Endonasal biopsy: In this technique, your doctor will use a nasal speculum and a good light to look inside your nose. Your doctor will take a piece of the suspicious tissue using a forcep.

Direct rigid nasal endoscopy: Here, your doctor will place a steel rod telescope into your nose. Then, either through a video projection or looking right through the telescope, he or she will place a forcep into your nose (or nasopharynx or sinus) and take a piece of any suspicious tissue.

Biopsy of neck masses

If there is also a lump in the neck, your doctor might decide to biopsy that as well. There are a few different ways to do a biopsy of the neck.

Fine needle aspiration biopsy: The most common and easiest way to biopsy is fine needle aspiration biopsy (FNAB), in which a tiny needle is placed into the tumor and some cells are drawn out through a syringe. The pathology doctor, known as a cytologist or cytopathologist, will then immediately look at the cells under the microscope and let your doctor know if there were enough cells to make a diagnosis. A number of “passes” might be done to increase the likelihood that there are enough cells to make a diagnosis. The final diagnosis may take a few days to come back, so be patient.

DIFFERENT TYPES OF FINE NEEDLE ASPIRATION BIOPSIES

“By Feel”FNAB

Ultrasound Guided FNAB

CT-Guided FNAB

When Your Doctor Might Use This Technique

If the lump can be easily felt by your doctor

If your doctor thinks it will be difficult to get the needle directly into the lump with certainty

If your doctor doesn’t think he or she will be able to get into the tumor by feel or with ultrasound guidance

What to Expect

Your doctor will feel the lump and place a tiny needle directly into it to extract some cells.

Your doctor will use a gentle probe on your face or neck, identify the tumor with the ultrasound and then watch the needle go directly into the tumor on the ultrasound machine.

You will be placed into a CT scanner, and a few low-dose CT scans will be performed—first to localize the tumor and then to make sure the needle that is placed is actually within the tumor.There is new technology known as fluoroscopic CT scanning, in which the radiologist can quickly take a few scans without leaving the room, in order to quickly insert the needle into the right place.

Core biopsy: Core biopsy is an alternative to fine needle aspiration. A core biopsy is done in the same way as an FNA biopsy, but it uses a larger needle and removes a core of tissue from the tumor rather than just a few cells. The likelihood of false positives and false negatives is much lower with a core needle biopsy than with a fine needle biopsy.17 Spiro RH, Thaler HT, Hicks WF, Kher UA, Huvos AH, Strong EW. The importance of clinical staging of minor salivary gland carcinoma. Am J Surg. 1991 Oct;162(4):330-6.

Open neck biopsy: An open biopsy involves making an incision over the tumor and removing a piece or all of the tumor to make a diagnosis. An open biopsy of a neck mass is performed through an incision over the lump, and either a piece (incisional open neck biopsy) or the entire lump (excisional open neck biopsy) is removed to make a diagnosis. Except in a few special circumstances (such as if the tumor is likely a lymphoma or if other methods of diagnosis have not worked), this method should not be used to find the diagnosis of a neck mass.

Serology

Serology, or blood serum testing, is not used as often in other head and neck cancers. However, if NPC is suspected or known, your doctor might check your blood to see if your body has made proteins to fight the Epstein-Barr Virus. In some cases, checking for free DNA of the virus may also help with screening. Doctors do not completely agree about the exact uses of these tests at this time.